Ever have a day when everything went wrong? Say you predicted you would have a normal college day. But your alarm clock didn't ring. Already running late, you couldn't find your backpack (or whatever you use). Finally you stagger out the door, but your car won't start. Later, you find out you missed a surprise quiz. It's a bit like that for the entire field of forecasting... here's why.

Spoil Sport of Prediction #1: the Observer Effect

To figure out what happens next, you need to know where things are now. For example, if you hit a billiard ball, you can't predict what will happen next unless you know the current layout of the pool table. Unfortunately, as a matter of principle, the observer effect holds that the act of finding out "where things are now" (i.e. determining the current state of the system of interest) changes it to something else (i.e. perturbs the system). In physics this is most noticeable for very small things or faint effects. In principle though, it applies to any scenario.

. . . Can you think of some examples of the observer effect?
Does the observer effect help understand any of the topics of interest?
. . . Cybernetics
. . . How long will Homo sapiens sapiens be the dominant species on planet Earth?
. . . Broadband Internet speed/download speed projections
. . . Speed of future commercial air travel
. . . Will Microsoft lose dominance in the software market?
. . . Future of more automated driving
. . . Future of home energy use, such as with lighting
. . . How will the average human lifespan change?
. . . How will DNA database(s) grow and be used?
. . . Future of "green energy" technologies
. . . Future markup for data

. . . Ever try to look at the back of your head using two mirrors? It makes you move your head around!

. . . If you use a camera with flash to take a picture of airborne dust in a dark room, the light will affect the dust a little bit. Or dust in a sunbeam. Or dust in the air in a dark room viewed with a flashlight

. . . What about watching a pool game?

. . . What about measuring the weather for weather forecasting?

. . . What about measures of the economy printed in newspapers?So you've controlled the observer effect

. . . And now, let's try it with a laser pointer and a piece of black plastic cut from a notebook cover!

The Uncertainty Principle says that you cannot know both the position and momentum of a particle exactly. The uncertainty in position, delta x, time the uncertainty in momentum, delta m, = h/4*pi where h is Planck's constant. Since momentum is velocity times mass, we have uncertainty about velocity too (and mass too, for that matter). So there is uncertainty about place, velocity, and mass of any object. Let's focus on position and velocity, out of tradition.

To fully describe a system, such as the universe, or some smaller part of the universe, we need simply list the position and velocity of everything in it. How many numbers are needed to describe the position? Three, a side-to-side location, a front-to-back location, and a height (also known as x, y, and z coordinates). How many numbers are needed to describe the velocity, where velocity consists of a speed and a direction? Three - a side-to-side speed, a forward backward speed, and an up-down speed. This concept is easiest to visualize in a 2-D simplified example.

So we need six numbers for every object to fully describe the system (actually seven, since each object has a mass as well). Unfortunately those six numbers are in principle impossible to get with full accuracy, beause they include both velocity and position values. The Uncertainty Principle tells us that higher accuracy for one results in lower accuracy for the other.
In short, if the observer effect doesn't stop our prediction ambitions, the Uncertainty Principle will. But what if we can control both, enough at least to predict futures with confidence? Alas, we're not out of the woods, because of the esoteric physics phenomenon called "quantum tunneling."Spoil Sport of Prediction #3: Quantum Tunneling
According to quantum theory, objects are not as localized in space as we intuitively think. Instead, they have wave-like characteristics and are actually "smeared" over a space within which they may be said to exist with some probability at each point within that space. A tiny object like a subatomic particle, if near enough to a thin barrier, thus has a certain probability of being on the other side of the barrier. If it is, it has thus "tunneled" through the barrier without making a hole in it. This is quantum tunneling. http://www.youtube.com/watch?v=6LKjJT7gh9s&NR=1&feature=fvwp
Actually, the term quantum tunneling is applied to the ability of objects to "tunnel" through other kinds of barriers than a solid one. For example, consider the somewhat notorious example of an idealized pencil balanced on its tip.
Source: http://2.bp.blogspot.com/_cldxKGOzgeM/Sb-pzadDENI/AAAAAAAACFM/-u4n2s3-5q8/s400/A+pencil+on+it%27s+tip.JPG
If the tip sharp, except for a tiny flat spot (say, a couple of atom wide) it might be difficult to balance, but one might think that with sufficient care it could be done. Well not exactly. Because the pencil is actually "smeared" a little bit, it has a certain, rather small probability of being tipped enough to lose balance and fall. Since the smearing is symmetric, it could in fact fall in any direction. The probability of being tipped enough to lose balance is small enough that a single such pencil would be unlikely to fall for a long time (Easton, 2007, p. 1103). But get enough pencils together and one will fall soon enough. For example, balance an array of 1000 x 1000 pencils and one will fall, knocking over other pencils and leading to a general domino-like conflagration with an average (but unpredictable) delay of around a month. What pencil will start the general crash and in what direction the pencils fall is impossible to predict.
But maybe the system we're interested in predicting the future of is not so finely tuned. Maybe we can handle the Observer Effect, the Uncertainty Principle, and quantum tunneling adequately for our system. Our troubles are still not over.Spoil Sport of Prediction #4: the Butterfly Effect
The idea: a butterfly flapping its wings will create a small atmospheric disturbance. That disturbance will propagate unpredictably. Some time later (how long?), the paths of hurricanes will be determined by those tiny flaps.
One mathematical description of atmospheric cycles whose future behavior depends seemingly unpredictably on small present events, may be modeled by a special kind of water wheel.http://www.youtube.com/watch?v=zhOBibeW5J0http://www.youtube.com/watch?v=VumQmC2jJbU&NR=1http://video.google.com/videoplay?docid=-355587954903008142http://maxwell.ucsc.edu/~drip/talks/lorenz/media/wiel.MPG
“When our results concerning the instability of nonperiodic flow are applied to the atmosphere, which is ostensibly nonperiodic, they indicate that prediction of the sufficiently distant future isimpossible by any method, unless the present conditions are known exactly. In view of the inevitable inaccuracy and incompleteness of weather observations, precise very-long-range forecasting would seem to be non-existent.” [emphasis added]
— Edward N. Lorenz
Let's discuss what butterflies might affect our topics of interest:

So you think you've controlled the Butterfly Effect and all those others? Then welcome to...

Spoil Sport of Prediction #5: External perturbations
To figure out what happens next, you need to know where things are now. But you also need to know what outside influences will impinge on the system between "now" and "next," whenever that is. Those influences can affect the evolution of the system - that's why they're called "influences."

Imagine, for example, the Lorenz water wheel, but while it's raining. Every raindrop is another butterfly whose tiny actions change the direction of the wheel at some future time. More generally, every external nudge to a system is like that butterfly.

Recall pre-"discovery" Easter Island and the canoes
A big palm tree was needed to build a good canoe
A good canoe was needed to get plentiful seafood
Hence the question made in Earth 2100 about cutting down the last palm tree
It's from Diamond's book; let me read the passage now (p. 410)Why societies can collapseFailure to recognize a critical problem before it happens
Example: foxes and rabbits in Australia
Anasazi civilization (Arizona) did not anticipate local climate change (drought)
France built the Maginot line for defense, but lost WWII in mere weeks
Etc. (can you think of any)Failure to recognize the problem when it happens
Examples: any slow-moving trend obscured by short-term effects
Recall noise-and-signal (http://computinginformationandthefuture.blogspot.com/2009/10/trend-analysis.html)
Also called "creeping normalcy"
Let me read from Diamond (p. 426) more about the palm trees...
Etc. (Can you think of any examples?)Failure to try to solve the problem after it is recognized
Why on Earth would anyone or any group do that??
Yet according to Diamond this "failure is the most frequent"!
. . . Failure may benefit influential special interests that therefore push it
. . . Greenland Norse leaders kept cows (unsuited to the cold)
. . . The few pike fishermen stocked pike in Montana waters, destroying trout for the many more trout fishermen (p. 427)
. . . "Throughout recorded history, actions or inactions by self-absorbed kings, chiefs, and politicians have been a regular cause of societal collapses" - p. 431
. . . Any examples of benefiting a few at the expense of the rest?
. . . Is this rational behavior?
. . . Unregulated access to common resources
. . . . . . "If I don't take as much as I can, someone else will"
. . . . . . Pretty soon it's gone!
. . . . . . Any examples?
. . . . . . Is this rational behavior?
. . . . . . Solutions?Irrational causes of societal collapse
. . . Beliefs that aren't right
. . . Taking a gamble and losing
. . . Etc. (any others you can think of?)Failure to be able to solve the problem
Greenland Norse colony: "The cruel reality is that...Greenland's cold climate and...limited...resources have posed an insuperably difficult challenge to...a long-lasting sustainable economy." - p. 436

Spoil sport of prediction #7: The care horizon

How much is the future of the human race worth? We'll increase it later, but let's start with an admittedly bargain basement $100. If you had $98.04 now, and put it in the bank at an interest rate of 2% per year, then in a year you'd have $100. That means getting $100 one year from now is only worth having $98.04 now, at least from a "Time Value of Money" perspective. Similarly, getting $100 in 2 years is only worth $96.12 now, because adding 2% to $96.12 gives $98.04 in one year, and compounding by adding another 2% gives $100 a year later. Extending this reasoning further, the human race in a modest 233 years would be worth just under a dollar now. In 466 years? Less than a penny.

It's safe to say that a hundred dollars is an underestimate for the value of the entire human race, at least to us. So let's increase it to a fair (or at least fairer) price. We might multiply the number of people by the value of the life of each and every person on the planet. What is the value of a person's life? Economics (known as the dismal science, even to economists) tells us that the de facto value society places on a human life can actually be calculated, and courts of law in fact sometimes do such calculations. Answers vary, of course, but a few million dollars is often not that far off the mark. Multiply that by the number of people in the world and you get a biggish number, $100 quadrillion at the most for the value of the human race.

But wait - maybe you don't trust the financial and legal wizards with something so important. After all, we already trust them with some pretty important things, and they periodically betray that, seriously screwing things up. Maybe we should use a higher number, just to be more sure we aren't under-valuing ourselves.

How about a dollar for every single atom in the known universe? That's around $10^80 (1 followed by 80 zeroes dollars)? It is a lot of cash. Way (way way) more than the United States has ever printed. There are literally not enough atoms in the known universe to even print that much money. Yet, if that is the value of humanity's existence 9070 years from now, the value at present would be...$100! A scant 466 years after that? Less than a penny. How about the present value of humanity existing in a million years? The answer is a fraction of a penny so tiny that popular spreadsheets, calculators and computer programming languages can't even state it. They typically just think it is 0, but if you must know, it's actually about $0.000<insert 8,513 more zeroes here>0001.

Wait - someone in the back has a question - yes? "But it's not just the value in year on million we're after. We also need to add in the value in year 1,000,001, year 1,000,002, etc., forever and ever. That's got to add up, eventually." Well, only a little, it turns out. The value now is "bigger," but still less than $0.000<insert 8,511 more zeroes here>0001 even at a dollar an atom. The upshot of all this is that there is no good reason to care whether humanity exists in ten thousand or a million years, at least according to the time value of money approach favored by economists. Therefore there is no need to plan that far into the future, or go to trouble and expense to preserve the Earth indefinitely, or even to bother predicting that far ahead. The time value of money seems indeed to be a spoil sport of the prediction game.

Making it personal. Maybe you are still unconvinced. Such sophistry fails to capture the real facts at a gut, common sense level, you might say. Then consider the following argument.

You care about yourself, so you don't want humanity to end while you are still alive (it might not be pleasant). You care about your children (or you will if you have any some day, or maybe you care about some or even all other children), so you don't want humanity to end during their lifetimes, even if you are already gone. You probably even care (or will care) about your grandchildren because you will hopefully get to know them personally. Furthermore, you care about their grandchildren (if maybe a little less) simply because you care about your grandchildren, who care about theirs. But you have no gut level reason to care about the generations after that, because neither you, nor anyone you care about will ever know them. To put it another way, how much do you care about your grandparents' grandparents, and how much did they care about you? Still care in some more abstract, dispassionate sense? Then see the previous paragraph.

Maybe you are a fast enough breeder, and long enough liver, that you'll care about your great grandchildren and theirs, instead of just grandchildren. Yet that is still only 6 generations into the future, not even the biblical 7, a couple of centuries or so at the most. So relax, quit worrying, eat dessert first.... In particular, don't bother with predicting past the 2-century "care horizon," because there's little point to it. The care horizon is, thus, our last spoil sport of the prediction game.

Postscript. Do you still want to predict the future, despite all the arguments to the contrary? If so, you are like me. Read on!